Metrology targets are designed to enable the measurement of parameters that indicate the quality of wafer production steps and quantify the correspondence between design and implementation of structures on the wafer. Metrology targets as specific structures optimize the requirements for device similarity and for optical measurability.
Monitoring the exposure parameters such as the effective dose and focus enhance metrology target related techniques and allow better process and product monitoring. As target features depend on exposure parameters, measuring the exposure parameters enhances the metrology results for target structures.